Kinetid structure in Choanocytes of Sponges (Heteroscleromorpha): Toward the ancestral Kinetid of Demospongiae

Every large clade of Eukarya has its own pattern of kinetid (flagellar apparatus) structure, which is stable and specific within the group, thereby being a good phylogenetic marker. The kinetid structure of sponge choanocytes might be a candidate for such marker for the phylogeny of Porifera. Kinetids of two heteroscleromorphs, Halichondria sp. (Suberitida) and Crellomima imparidens (Poecilosclerida), have been investigated here for the first time, and a reconstruction of the kinetid for each species is provided. The kinetids of both species comprise a flagellar kinetosome with a nuclear fibrillar root, a basal foot and satellite producing microtubules; a centriole is absent. Good resolution images reveal a new thin structure, the axial granule, in the flagellar transition zone which might be present in other sponges. The comparison of kinetids in investigated sponges revealed three types of kinetid in Demospongiae, and their distribution in the taxon has been shown on a molecular phylogenetic tree. Kinetid characters of the common ancestor of Demospongiae are discussed. J. Morphol. 277:925–934, 2016. © 2016 Wiley Periodicals, Inc.     

Effect of excretory-secretory products of some fouling organisms on settling and metamorphosis of the larvae of <Emphasis Type="Italic">Styela rustica</Emphasis> (Ascidiae)

The effect of the excretory-secretory products of some fouling animals on the settling and metamorphosis of larvae of the solitary ascidian Styela rustica was assessed. The substances secreted by the sponge Halichondria panicea stimulated settling of larvae, but concurrently blocked their metamorphosis. The excretory-secretory products of the mussel Mytilus edulis and the ascidian Molgula citrine did not affect settling of the S. rustica larvae but impeded their subsequent development. Water conditioned by the bivalve Hiatella arctica, stimulated settling and, apparently, metamorphosis of the larvae of S. rustica. The chemical substances produced by adult individuals of S. rustica facilitated settling of conspecific larvae but slightly delayed their metamorphosis.     

Isolation and characterization of microsatellite loci in the intertidal sponge Halichondria panicea

GA‐ and CA‐enriched genomic libraries were constructed for the intertidal sponge Halichondria panicea. Unique repeat motifs identified varied from the expected simple dinucleotide repeats to more complex repeat units. All sequences tended to be highly repetitive but did not necessarily contain the targeted motifs. Seven microsatellite loci were evaluated on sponges from the clone source population. All seven were polymorphic with 5.43 ± 0.92 mean number of alleles. Six of the seven loci that could be resolved had mean heterozygosities of 0.14–0.68. The loci identified here will be useful for population studies.     

Tissue sloughing in the sponge Halichondria panicea: a fouling organism prevents being fouled

Summary Specimens of the sponge Halichondria panicea Pallas kept in running sea-water aquaria at 15° C slough off their complete outer tissue layer in regular intervals of three weeks. Sloughing starts at the rim of the oscula and extends over the whole surface within two weeks. Microscopic inspection of the tissue flakes shows them to harbour large numbers of different live organisms, as well as biogenic debris such as pieces of copepod carapaces and diatom frustules. No such community is found on freshly sloughed sponge tissue. After sloughing, the surface skeletal structure of H. panicea is markedly altered, as the characteristic halichondroid reticulum has been replaced by the irregular spicule array typical for the inner sponge tissue. When H. panicea is kept in closed aquaria filled with 0.2 m filtered sea-water, no sloughing occurs during 3 months of maintenance. As those sponges shedding their outer tissue grow steadily at the same time, the tissue sloughing can be regarded as a reaction to sedimentation of organic material and settlement of small organisms on the sponge surface. The sponge thus counteracts clogging of its ostia and prevents the establishment of a micro fouling community on its surface, inhibiting further fouling processes.     

SEQUENTIAL REPRODUCTION BY DIFFERENT TYPES OF SPECIMENS OF THE ESTUARINE SPONGE,HALICHONDRIA SP., WITH AN EMPHASIS ON REPRODUCTION OF POSTLARVAL SPECIMENS

Young specimens of Halichondria sp., recently developed from larvae (postlarval specimens), engage in sexual reproduction; and reproductive activity increases with specimen size. Reproduction by such specimens takes place primarily during a period after breeding by the parental generation has declined. This fact suggests that environmental conditions are favorable for reproduction for an extended period of time and that reproduction is to a large extent under endogenous control.     

海洋抗肿瘤活性大环内酯类化合物化学成分研究近况

最近,人们已从多种海洋生物中发现许多具有应用价值的生理活性物质。其中,抗肿瘤活性物质的开发研究尤为盛行。目前,人们已经分离得到许多在体内试验中具有明显抗肿瘤活性的化合物,并且确立了它们的化学结构,其中包括类萜类化合物、生物碱,肽类化合物、大环内酯类化合物、类前列腺素化合物、聚醚类化合物等。其中,已有数种大环内酯类化合物很有可能作为抗癌药物进入临床。bryostatin 1则是它们的代表性化合物之一。目前,美国National Cancer Instituie已经开始对该化合物进行临床研究。它是由作者(釜野)研究小组在美国亚利桑拿州立大学癌研究所开发研究出的一种新型化合物,经过进一步研究又分离得到了bryostatin 2(24)～13(35),并确立了它们的化学结构。因此,本文将对bryostatin类化合物的化学性质以及其生理活性作详细地综述。另外,还将论述halichondrin类化合物(14～21)和Aplyronine(22)。它们是最近几年在日本发现的,在体内试验中具有很强的抗肿瘤活性的一系列新型化合物。再者,本文还将概述其它一些重要的、具有抗肿瘤活性的大环内酯类化合物,即aplysiatoxin(Ia～Ic), latrunculinA(2), acutiphycin(3),tedanolide(4), swinholide A(5), bistheonellde A(7a), amphicinolides(8～10), kabiramides(11a 11e), ulapualide(12a, 12b)以及patellazole B(13)。     

Bacterial diversity in the breadcrumb sponge Halichondria panicea (Pallas)

The aim of this study was to investigate the diversity and variability of bacterial communities associated with the marine sponge Halichondria panicea with respect to tissue compartmentalization as well as seasonal and small-scale geographic variation. Diversity of microorganisms in sponges was investigated recently, but work on the variability and succession of associated bacterial communities is rare. Despite some information on Pacific and Mediterranean sponges, it is still uncertain whether bacteria and sponges are specifically associated. In this study, H. panicea specimens were sampled throughout the year at different stations around the island of Helgoland (North Sea) and investigated using molecular tools. The bacterial community associated with H. panicea was diverse, consisting of one denaturing gradient gel electrophoresis (DGGE) band occurring in most 'tissue' samples and additional variable bands. Variability was observed between different sponge fractions (i.e. the aquiferous system and the 'tissue'), sampling locations, and sampling dates. A PCR-DGGE specific for the Roseobacter group of marine Alphaproteobacteria displayed low diversity and a marked similarity between all samples. Phylogenetic analysis also pointed to specific Alphaproteobacteria of the Roseobacter group, which was predominant in most sponge 'tissue' samples. We conclude that H. panicea harbour a specific Roseobacter population with varying bacterial co-populations occurring seasonally or on a small-scale geographically, sometimes even dominating the bacterial community.     

南海软海绵Halichondria sp.化学成分研究

为了寻找有生物活性的次生代谢产物,对从采集自中国南海的软海绵(Halichondria sp.)进行了化学成分研究,从中共分离得到了9个化合物,并对部分化合物进行了抗菌活性测试。根据现代波谱技术并结合文献数据,鉴定化合物的结构为:1,2,3,4-四氢-3-羧基-2-卡波林(1),色氨酸(2),环(异亮氨酸-脯氨酸)(3),开环(脯氨酸-缬氨酸)(4),环(丙氨酸-脯氨酸)(5),胆甾醇(6),二-(2-乙基己基)邻苯二甲酸酯(7),邻苯二甲酸正丁异丁酯(8)和邻苯二甲酸二异丁酯(9)。     

基于皱皮软海绵宏基因组的PKS基因筛选的研究

提取皱皮软海绵及其共附生微生物的宏基因组总DNA,使用聚酮合酶(PKS)基因的酮酰合酶(KS)域引物PCR扩增PKS基因片段获得一条671bp的片段,以pUCm-T vector为载体将该基因片段克隆到大肠杆菌中,从阳性克隆中分离出PKS基因片段,测序推导出氨基酸序列。通过BLAST比对发现此氨基酸序列与红细菌目的Rhodobacterales bacterium PKS基因KS域的氨基酸序列有96%的同源性。通过基于氨基酸序列的系统发育分析,推测此筛选得到的PKS基因属于trans-AT型。本文首次证实了皱皮软海绵中存在细菌来源的PKS基因。     

Fatty Acids from the Sea of Japan Sponge Halichondria panicea

The fatty acid (FA) composition of total lipids isolated from the marine sponge Halichondria panicea inhabiting Peter the Great Bay of the Sea of Japan was studied. GC and GC-MS techniques were used in identification of 63 FAs, with the main attention being paid to FAs with 14–22 carbon atoms. 4,8,12-Trimethyl-13:0 FA was for the first time identified as a main saturated FA, along with the branched FAs br-25:1, br-27:1, and br-27:2. The contents of arachidonic, eicosapentaenoic, docosapentaenoic, and the major demospongic acids [26:3(5,9,19), 26:3(5,9,17), 27:3(5,9,20), and 28:3(5,9,21)] considerably differed from those previously found for H. panicea, which may be due to seasonal changes in the species composition of organisms consumed by the sponge.